The mountains shall bring peace - Perhaps mountains and hills are here taken in their figurative sense, to signify princes and petty governors; and it is a prediction that all governors of provinces and magistrates should administer equal justice in their several departments and jurisdictions; so that universal peace should be preserved, and the people be every where prosperous; for שלום shalom signifies both peace and prosperity, for without the former the latter never existed.
But what is the meaning of "the little hills by righteousness?" Why, it has no meaning: and it has none, because it is a false division of the verse. The word בצדקה bitsedakah, in righteousness, at the end of Psalm 72:3, should begin Psalm 72:4, and then the sense will be plain. Psalm 72:3; : "The mountains and the hills shall bring prosperity to the people." Psalm 72:4; : "In righteousness he shall judge the poor of the people: he shall save the children of the needy, and shall break in pieces the oppressor."
The effects, mentioned in the fourth verse, show that King Solomon should act according to the law of his God; and that all officers, magistrates, and governors, should minister equal rights through every part of the land. The Septuagint has the true division: Αναλαβετω τα ορη ειρηνην τῳ λαῳ σου, και οἱ βουνοι· Εν δικαιοσυνῃ κρινει τους πτωχους του λαου, κ. τ. λ . "The mountains shall bring peace to thy people, and the hills: In righteousness shall he judge the poor of thy people," etc.
The mountains shall bring peace to the people - The idea in this verse is that the land would be full of peace and the fruits of peace. All parts of it would be covered with the evidences that it was a land of quietness and security, where people could pursue their callings in safety, and enjoy the fruit of their labors. On the mountains and on all the little hills in the land there would be abundant harvests, the result of peace (so strongly in contrast with the desolations of war) - all showing the advantages of a peaceful reign. It is to be remembered that Judea is a country abounding in hills and mountains, and that a great part of its former fertility resulted from terracing the hills, and cultivating them as far as possible toward the summit. The idea here is, that one who should look upon the land - who could take in at a glance the whole country - would see those mountains and hills cultivated in the most careful manner, and everywhere bringing forth the productions of peace. Compare Psalm 65:11-13. See also the notes at Psalm 85:11-12.
And the little hills, by righteousness - That is, By the prevalence of righteousness, or under a reign of righteousness, the little hills would furnish illustrations of the influence of a reign of peace. Everywhere there would be the effects of a reign of peace. The whole land would be cultivated, and there would be abundance. Peace always produces these blessings; war always spreads desolation.